Current non-invasive monitoring of uterine activity in the pregnant woman is accomplished by tocotonometer devices which monitor continuously the hardness of the abdominal wall by measuring the force needed to push against the device. These electro-mechanical devices must be located over the fundus (top) of the uterus, fastened to the abdomen with a belt and electronically connected to a fetal monitor. The devices are placement and artifact sensitive, bulky and uncomfortable for the patient, require frequent adjustment and they are delicate and expensive. The objective of this project is the development of a soft air- filled pressurized "bladder" ("air-cushion tocotonometer") that is held onto the abdomen with a belt. The bladder is compressed between the belt and the uterus and the pressure increase is measured by any variety of standard pressure measuring devices. It may be necessary to develop and include an electronic transducer interface to amplify the signals generated by the pressure changes. The performance is expected to be equivalent to standard tocotonometers. They will be comfortable, rugged and inexpensive. In Phase I we will demonstrate engineering models of the "air- cushion tocotonometer", characterize their performance and conduct clinical trials to confirm our in-house findings.